Salvage of the Maurienne

On the 7th of February in 1942, the master of the 3,259 GRT freighter Maurienne was dealing with some frozen pipes in one of the holds. He subsequently directed a worker to use an acetylene torch to thaw said pipes, and a fire later erupted in that same location. When conventional efforts to extinguish the fire were unsuccessful, the master ordered the scuttling of his vessel, which in turn resulted in the almost total loss of the cargo after she capsized at the pier (as noted on page 21 of International Maritime Conventions: Volume 1, which also details a legal action brought against the shipping firm by the owners of three crates and one drum of shoe leather). 

Built in Denmark in 1938 as a refrigerated vessel to transport bananas, and only taken over by the Canadian Government at the beginning of the war, Maurienne was a new vessel . Coupled with the fact that the 324-foot vessel was also blocking the use of a portion of Pier 27/28 in the wartime Port of Halifax, her salvage would presumably have been a priority, and therefore she was subsequently salvaged by Foundation Maritime. 

The capsized freighter Maurienne.

Another view of the capsized ship, with the superstructure facing the pier. I'm assuming these photos were taken right after the sinking, such that reserve air in the hull was keeping the hull barely afloat, as later images suggest the hull was farther below the surface during the salvage work, and these photos do not appear to me to have been taken at low tide.

The salvage of the Maurienne was undertaken by Foundation Maritime in two main phases: righting, and then refloating. To begin, at least two cofferdams were constructed on the side of the ship to allow work to continue in the dry - two righting masts had to be attached to the side of the ship.

By June 24, 1942, Cofferdam #2 was ready to accept the righting mast. The two legs of the righting mast will go into the two openings marked with an "X". The "No.1" in the corner of the image refers to the image number, and not that of the cofferdam (which I got from the image caption).

A pontoon supports a diving platform alongside Cofferdam #2 - the platform seems to be slung from the two arms. At least two divers sit in their suits on the platform. 

Cofferdam #1 (background, with mast installed) and Cofferdam #2 (foreground). A support pontoon lies alongside each cofferdam, presumably carrying the pumps to keep each cofferdam dry. Foundation Scarboro, without her shear legs installed, is to the left of the image.

Foundation Scarboro starting to lift the righting mast into place in Cofferdam #2.

The righting mast being installed in Cofferdam #2.

Workers help drop the righting mast into place within Cofferdam #2, as seen from atop the rotating crane cab on Foundation Scarboro.

Cofferdam #1 with the righting mast installed. A bridge (without railings!) extends back to the Pier at the right of the photo. So much for Health and Safety.

Righting masts installed, but with cofferdams removed, to show how the masts are attached to the side of the ship.

By July 26, 1942, the ship was ready to be righted. Tension was taken up on the cables attached to the two righting masts, and the ship was slowly righted. Presumably the hull was anchored to the bottom in some manner to ensure the hull rotated, and was not simply pulled away from the pier. 

Note: Mac Mackay of Shipfax was kind enough to tell me that this type of salvage is properly referred to as "parbuckle salvage", or "parbuckling". The "righting masts" as I call them above are properly called "bents".

Righting the Maurienne.

Just past 45 degrees.

Once righted, there was a release of air trapped in the ship.

Righted, but not yet refloated.

Believe it or not, this appears to have been the easy part of the salvage. Maurienne was still sitting on the bottom of Halifax Harbour, and needed to be refloated. Foundation Maritime elected to build a new, larger, cofferdam around the majority of the ship's deck. The cofferdam extended above the surface of the water at high tide (you can see the stains from the tidal cycles on the side of the cofferdam) so that the interior of the ship could be pumped out. 

Construction of the new cofferdam proceeds around a forward mast, ahead of the bridge which appears to the left of the image.

The view from inside the cofferdam, taken looking forward from aft of the funnel. To the right is a wooden frame that appears to be used to handle a couple of pumps. This may have been positioned over one of the ship's holds. 

The view from the deck of the ship itself, within the cofferdam.

Two of the Jaeger engines used during the salvage - I'm assuming these were diesel engines used to power centrifugal pumps.

The pumping operation is underway, and a deckhouse at the stern has just broken the surface.

Pumps running from inside a cofferdam to bring Maurienne to the surface.

Pumping continues. Taken on the port side this time, the ship's nameboards can be seen displaying "Maurienne". 

The cofferdam support framework on the starboard side next to the funnel, with the pumps running.

Some of the array of pumps that was used to bring Maurienne back to the surface. 

In conjunction with the pumping operation, barges with shear legs also appear to have been lifting at the bow, ahead of the cofferdam. These may have helped to keep the ship on an even keel during the refloating operation.

Pumps running from the cofferdam, with the bow gunwale appearing to the right. The barges with shear legs can also been seen lifting here. 

Returning to the surface, though still with a list to starboard.

With pumps still running, Maurienne arriving at the surface. The deckhouse from Image #120 above can be seen here, just behind the cofferdam.

In November of 1942, while Maurienne was once again afloat, work was ongoing and the ship still looked much the worse for wear.

The refloated Maurienne. What I assume are the remains of the attachments for Righting Mast #1 can be seen just above the waterline just forward of the bridge.

Maurienne from aft.

After the war ended, Maurienne was returned to her original owners and refitted once against for refrigerated cargo. She was sold several times after 1953 (and renamed), and suffered another fire in 1963 in Hong Kong that led to her scrapping.

The entire gallery of photos of the salvage operation can be seen here:

https://smcclearn.smugmug.com/Nautical/Foundation-Maritime-storage/4064-Maurienne/n-xh3bMC/i-4WGpSCS/A

Some of the photos appearing here came with captions explaining the procedure, but most did not, and I have interpreted (e.g. guessed) them to the best of my ability.

Bibliography & Acknowledgements:

Berlingieri, Francesco. (2014). "International Maritime Conventions: Volume 1 - The Carriage of Goods and Passengers by Sea". Informa Law, New York.

Bertke, Donald A; Smith, Gordon; Kindell, Don. (2013). "World War II Sea War - Volume 5". Bertke Publications, Dayton, Ohio, USA. Viewed online.

Nova Scotia Marine Heritage Wreck Database

Wrecksite.eu https://www.wrecksite.eu/wreck.aspx?35482

Photos from the AECON collection.

Salvage of the Maplebranch

On August 13th 1934, the Royal Navy's Danae-class cruiser HMS DRAGON was entering the Market Basin in the Port of Montreal. While trying to avoid contact with a third vessel, the also-maneuvering Saguenay Trader, DRAGON came into contact with the oil bunkering tanker Maplebranch, causing the latter to sink. At least, that was the defence provided by DRAGON's commanding officer, Frederic Wake-Walker, when he was later sued (successfully) by Maplebranch's owners. 

A partially-sunken Maplebranch sitting alongside in the Market Basin, with the offending HMS DRAGON in the background.

Maplebranch viewed from aft. 

The salvage was contracted to Foundation Maritime. Already sitting on the bottom and completely full of water, the salvage was somewhat involved. As the wreck was taking up valuable space in the port, there would presumably have been considerable pressure to remove it quickly. 

Salvage crews went about building a cofferdam around the ship so that the wreck could be pumped out and re-floated. 

With a cofferdam constructed around the aft end of Maplebranch, pumping begins. 

A barge consisting of a platform constructed on two large pontoons supports what I assume is an air compressor used in the salvage.

Another view of the cofferdam around the aft end of the ship and ongoing pumping operations.

Maplebranch returning to the surface as pumping continues.

The view from the other side of the channel. The deep sea salvage tug Foundation Franklin can be seen to the right of the image, behind Maplebranch. 

Once refloated, Maplebranch was taken in tow by two smaller harbour tugs.

Maplebranch now afloat, and being moved by two tugs.

Unfortunately, I am unable to find any further online information on Maplebranch herself, neither photos of her from before the sinking, nor whether she returned to service after this incident or was subsequently scrapped. 

In searching, however, I did learn about HMS DRAGON's then-commander, Frederic Wake-Walker. (links go to Wikipedia). The collision with Maplebranch did not end his career; on the contrary, from 1938-39 he was in command of the battleship HMS REVENGE, and he achieved flag rank as rear-admiral commanding the 12th Cruiser Squadron. He was later appointed rear-admiral in command of all vessels off the Franco-Belgium coast during the evacuation of Dunkirk, and later still was appointed commander of the 1st Cruiser Squadron, during which time he was deeply involved in the hunt for the Bismarck. He was promoted to admiral in May 1945, but died unexpectedly in September of that same year. 

Unconnected to all of this, but of local interest, REVENGE was a frequent visitor to Halifax over the years, and in 1940 (under a subsequent commander) she managed to run down (and sink) the Battle-class trawler HMCS YPRES, then being used as a gate vessel for opening and closing the submarine nets across the mouth of the harbour. 

Working in India: Anatomy of a Hydro Project - Diversion Tunnel (Part 6)

In a previous post, I presented photos taken during a period of construction on the 62.5m high gravity dam on the Nathpa Jhakri Hydroelectric Project on the Satluj River. At the end of the post, I asked the question: "How do you build a dam in the middle of a river in the mountains?" When you are a steep sided mountain valley, you can't just divert the water around the dam site - or can you? Well, you can - but it isn't easy. In our case, it required a diversion tunnel cut through the rock of the mountain side around the dam site on the right bank. The diversion tunnel was completed before I ever arrived on site, and was presumably plugged with concrete (or possibly just the steel gate at the upstream end) after I left.

After the diversion tunnel had been originally laid out, a rock slide at the intended inlet location meant that the tunnel had to be doubled in length. It had to be constructed on the right bank, so that it would not interfere with the construction of the desilting chambers and head race tunnel on the left bank. 

Layout of the dam area, with the diversion tunnel shown on the left side of the diagram.

When I arrived on the project in February 1999, the tunnel would already have been pressed into service for the winter months. The tunnel was only designed to handle up to a certain maximum flow (I don't remember what it was, but probably in the range of 200-500 cubic metres per second (cumecs), but the Satluj River varied between around 80 cumecs in winter to a normal maximum of around 2000 cumecs in the summer. In springtime, river flow rates from a nearby government monitoring station would be watched carefully, and as flows approached the tunnel maximum, flows would be removed from the tunnel and rerouted through the dam site. Dam construction would halt during the summer in areas below the water level. 

A close-up of the Diversion Tunnel (DT) inlet cofferdam (taken in September 1999), which forced the river to flow through the dam site. Summer flows were far too much for the DT to handle, and would cause significant damage if allowed to flow through the tunnel, so it would be blocked up for the summer so that maintenance could proceed. In August 2000, this cofferdam would be eroded away during a serious flood event, and the DT became filled with silt almost to the roof of the tunnel. The DT Bailey Bridge can be seen spanning the gap over the tunnel inlet. This bridge had a fairly limited load capacity, and this caused problems on several occasions. The cofferdam has clearly had traffic over it for some time, and was probably used to bypass the bridge for heavy loads, although I do not remember for sure at this point. A loader and two trucks have begun to dismantle the cofferdam.

A tight fit - one of the 17 tonne gate anchor girders arrives by truck across the DT Bailey Bridge. The bridge had to be realigned and beefed up especially to take this load, and even so, this photo shows the slight deformation of the bridge due to the weight. There was only inches to spare on either side as the girder crossed the bridge.

The next few photos show the sequence of removing the diversion tunnel cofferdam. The cofferdam would be removed in lifts (or layers) from top to bottom, until just one lift was left. The excavator then began removing the final lift from the upstream end, and moving to the downstream end, from where the cofferdam across the river itself would be started. 

In October 1999, the Diversion Tunnel inlet cofferdam is breached to allow the river to flow through the DT. Shown here, an excavator has removed the bulk of the cofferdam, and is about to breach the dam. Note the larger rip rap on the sides of the channel to prevent erosion.

Water is starting to make its way through the reduced cofferdam. A Hindustan 1025 off-road dumper is receiving material from the excavator.

The 1025 dumper is back to take more material. This material is stockpiled nearby, to provide a source of material to construct the upstream cofferdam that will prevent the river from flowing through the dam site.

The diverstion tunnel cofferdam is mostly removed, allowing flow through the tunnel for the 1999/2000 dam construction season.

Once the diversion tunnel cofferdam was removed, a new cofferdam was constructed across the river itself, to force the water to pass through the tunnel, and leave the dam site relatively dry.

An excavator starts to push off the upstream cofferdam that will block the river flows through the dam site.

Construction continues on the upstream cofferdam. A 1025 dumper and a dozer have joined the work.

In a somewhat precarious position, a dozer pushes material out to the end of the cofferdam, and is very close to closing the gap to the south bank.

The completed cofferdam, taken in March 2000. It has been in place since October 1999. Taken from upriver, the dam site is visible in the background.

With the cofferdam in place, the dam site would be excavated to clear sediment deposits from the summer season, and construction would resume. At some point in the spring, the river flows would increase once again, and the river would be allowed to flow through the dam once again, and the diversion tunnel would be blocked off for inspection and maintenance. The next series of photos show the tunnel interior in August 1999.

This photo was taken within the DT inlet during the August 1999, with the DT inlet cofferdam visible in the background. The river flows during the summer months were too much for the DT to handle, and would have caused damage to the tunnel lining, so the flows were removed from the tunnel and the summer months were used for maintenance purposes. You can see temporary stairs (made of sand bags) and a temporary ladder that were used to gain access to the tunnel floor.

Another view of the DT inlet, with the same access ladder from the previous image off to the right. To the left you can see the beginning of the concrete lining that was at the tunnel entrance. You can see that a considerable amount of water is leaking past the DT inlet cofferdam, and it was always advisable to have rubber boots (gumboots in the local parlance, and Wellingtons or Wellies in the parlance of my British-extracted supervisor) on hand.

This photo was taken with available light from the DT inlet, looking in the downstream direction. The Chief Design Engineer is walking further into the tunnel, right under the gate shaft for the DT inlet gate. The gate was lifted by mechanisms stored in a chamber accessible from the road above, although I never saw it used so I am not sure what the point of it was. Perhaps it was supposed to be used for the permanent closure of the tunnel after the dam was constructed, to avoid draining the reservoir, while still allowing the option of diverting the flows during the winter months for dam maintenance. The tunnel at this location was partly lined with concrete to prevent erosion from the turbulence at the tunnel entrance, but beyond the gate shaft the native rock was lined with shotcrete, a form of sprayable concrete.

A view further into the DT, about as far as you could go without a flashlight - the lighting here is from spotlights provided to aid the inspection and maintenance of the tunnel. The roof, sides, and floor of the tunnel are lined with shotcrete, and you can see a number of rock bolt heads sticking out of the tunnel roof. The rock in the Himalayas is fairly soft and of low quality, as rock goes, and has a high content of mica which is very soft indeed. This rock does not fare well when put in tension, and so long rock bolts were drilled and grouted into the rock face to provide additional strength and to try and prevent rock falls. You can see the channel worn in the tunnel floor from the water flow.

I have previously alluded to a large flood during August of 2000 that caused significant damage to the project works, and I will dedicate a future post to the post-flood damage assessment, but I will cover the affects to the diversion tunnel in this post. The flood consisted of an initial 12 metre high wall of water that swept down the river, and then a period of higher than normal river flows after the initial event. While miraculously not heavily damaged, the diversion tunnel was still affected - the inlet coffer dam was swept away, and a good portion of it (along with other river sediment and gravels) was deposited in the tunnel, filling it almost to the tunnel roof (or crown). As part of the recovery during the fall of 2000, the diversion tunnel had to be cleared out before it could be used again. This meant that a good portion of the 2000-2001 dam concreting season was lost.

Before I ever arrived on the project, the Diversion Tunnel had to be increased in length by a factor of 2, because a large rock slide occured at the location of the intended tunnel entrance. This slide remained unstable, and the flood in August 2000 reactivated a portion of the slide and wiped out a portion of the road. The Diversion Tunnel inlet can be seen near the top right of the photo, with the Bailey Bridge spanning it. The flood occurred in August 2000, while the DT Inlet cofferdam was in place to protect the tunnel from the summer flows. Unfortunately, the flood breached the cofferdam, washed it away, and a portion of the river flowed through the tunnel. The water velocity in the tunnel must have been much reduced, which served to allow the sand and silt carried by the water to settle out and fill the tunnel.

Work has begun in this photo on removing the debris from the Diversion Tunnel slide. Near the top left of the photo, you can see a Hindustan 1025 dumper and Tata Hitachi excavator working on clearing the top portion of the slide. This provides some idea of the scale involved here.

This is the outlet of the Diversion Tunnel, almost completely filled with silt, sand, and rocks after the flood breached the inlet cofferdam. This tunnel would have to be cleaned out before construction work could resume on the dam.

This, again, is the outlet to the Diversion Tunnel, but after the cleaning operation had begun. To the right are two workers, to give some perspective to the size of the tunnel. Lighting has been added to the tunnel in order to facilitate the cleaning operation. This lighting would not normally be present, and would be removed again before the tunnel could be used for its intended purpose.

This photo was likely taken just inside the DT outlet opening, showing the ribs intended to support the opening.

My boss walks ahead of me in the DT as we approach where the equipment is working to remove material from the tunnel. Wouldn't you like to be the worker assigned to make adjustments to the electrical panel on the metal stand situated in a large puddle of water?

After walking around the bend in the last photo, we approach the wheel loader as it works at the face of the silt deposit. The tunnel was fairly cramped for equipment, and this loader would have to turn around before it could deposit a bucket of silt into a truck. I'm assuming they either used a loader because it was the only one they had available, or because there wasn't enough room for an excavator to swing its boom. The tunnel would have originally been excavated using dedicated tunnel machinery, but a lot of that equipment was lost during the flood, with the remainder busy elsewhere. 

After the loader backs off to fill a truck, my boss climbs the silt face to see what lies ahead of the cleaning operation. This photo was taken on January 10, 2001, a few weeks before I left India for good, so I probably didn't see the tunnel fully cleaned out before I left.

The diversion tunnel was returned to service after I left the project in January 2001, although I am not sure if it was used at all until the fall of 2001.